first ubiquitin-like (Ubl) domain located at the N-terminus of coronavirus SARS-CoV non-structural protein 3 (Nsp3) and related proteins; This ubiquitin-like (Ubl) domain (Ubl1) is found at the N-terminus of coronavirus Nsp3, a large multi-functional multi-domain protein which is an essential component of the replication/transcription complex (RTC). The functions of Ubl1 in CoVs are related to single-stranded RNA (ssRNA) binding and to interacting with the nucleocapsid (N) protein. SARS-CoV Ubl1 has been shown to bind ssRNA having AUA patterns, and since the 5'-UTR of the SARS-CoV genome has a number of AUA repeats, it may bind there. In mouse hepatitis virus (MHV), this Ubl1 domain binds the cognate N protein. Adjacent to Ubl1 is a Glu-rich acidic region (also referred to as hypervariable region, HVR); Ubl1 together with HVR has been called Nsp3a. Currently, the function of HVR in CoVs is unknown. This model corresponds to one of two Ubl domains in Nsp3; the other is located N-terminal to the papain-like protease (PLpro) and is not represented by this model.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 44662819   1 MFLTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINVI 70
Cdd:cd01807   1 MLITVKILQGKECTIEVSPTESVLTVKQLVAEQLNVPVSQQRLVFKGKTLADEHSLSDYSIGPGSKIHLV 70

ubiquitin-like (Ubl) domain found in ubiquitin-like proteins UBL4A and similar proteins; UBL4A, also termed GdX, is a ubiquitously expressed ubiquitin-like (Ubl) protein that forms a complex with partner proteins and participates in the protein processing through endoplasmic reticulum (ER), acting as a chaperone. As a key component of the BCL2-associated athanogene 6 (BAG6) chaperone complex, UBL4A plays a role in mediating DNA damage signaling and cell death. UBL4A also regulates insulin-induced Akt plasma membrane translocation through promotion of Arp2/3-dependent actin branching. Moreover, UBL4A specifically stabilizes the TC45/STAT3 association and promotes dephosphorylation of STAT3 to repress tumorigenesis. UBL4B is testis-specific, and encoded by an X-derived retrogene Ubl4b, which is specifically expressed in post-meiotic germ cells in mammals. As a germ cell-specific cytoplasmic protein, UBL4B is not present in somatic cells. Moreover, UBL4B is present in elongated spermatids, but not in spermatocytes and round spermatids, suggesting its function is restricted to late spermiogenesis. The function of UBL4A may be compensated by either UBL4B or other Ubl proteins in normal conditions. Both UBL4A and UBL4B contain a conserved Ubl domain with a beta-grasp Ubl fold, a common structure involved in protein-protein interactions.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 44662819   1 MFLTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINVI 70
Cdd:cd01807   1 MLITVKILQGKECTIEVSPTESVLTVKQLVAEQLNVPVSQQRLVFKGKTLADEHSLSDYSIGPGSKIHLV 70

Ubiquitin homologues; Ubiquitin-mediated proteolysis is involved in the regulated turnover of proteins required for controlling cell cycle progression

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 44662819      1 MFLTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINV 69
Cdd:smart00213   1 IELTVKTLDGKTITLEVKPSDTVSELKEKIAELTGIPPEQQRLIYKGKVLEDDRTLADYGIQDGSTIHL 69

UV excision repair protein Rad23; All proteins in this family for which functions are known are components of a multiprotein complex used for targeting nucleotide excision repair to specific parts of the genome. In humans, Rad23 complexes with the XPC protein. This family is based on the phylogenomic analysis of JA Eisen (1999, Ph.D. Thesis, Stanford University). [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 44662819     1 MFLTVKLLLGQRCSLKVSGQESVATLKRLVSR---RLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASInVIMQPLEKM 77
Cdd:TIGR00601   1 MTLTFKTLQQQKFKIDMEPDETVKELKEKIEAeqgKDAYPVAQQKLIYSGKILSDDKTVKEYKIKEKDFV-VVMVSKPKT 79

                          90
                  ....*....|..
gi 44662819    78 ALKEAHQPQTQP 89
Cdd:TIGR00601  80 GTGKVAPPAATP 91

ubiquitin-like (Ubl) domain found in ubiquitin-like proteins UBL4A and similar proteins; UBL4A, also termed GdX, is a ubiquitously expressed ubiquitin-like (Ubl) protein that forms a complex with partner proteins and participates in the protein processing through endoplasmic reticulum (ER), acting as a chaperone. As a key component of the BCL2-associated athanogene 6 (BAG6) chaperone complex, UBL4A plays a role in mediating DNA damage signaling and cell death. UBL4A also regulates insulin-induced Akt plasma membrane translocation through promotion of Arp2/3-dependent actin branching. Moreover, UBL4A specifically stabilizes the TC45/STAT3 association and promotes dephosphorylation of STAT3 to repress tumorigenesis. UBL4B is testis-specific, and encoded by an X-derived retrogene Ubl4b, which is specifically expressed in post-meiotic germ cells in mammals. As a germ cell-specific cytoplasmic protein, UBL4B is not present in somatic cells. Moreover, UBL4B is present in elongated spermatids, but not in spermatocytes and round spermatids, suggesting its function is restricted to late spermiogenesis. The function of UBL4A may be compensated by either UBL4B or other Ubl proteins in normal conditions. Both UBL4A and UBL4B contain a conserved Ubl domain with a beta-grasp Ubl fold, a common structure involved in protein-protein interactions.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 44662819   1 MFLTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINVI 70
Cdd:cd01807   1 MLITVKILQGKECTIEVSPTESVLTVKQLVAEQLNVPVSQQRLVFKGKTLADEHSLSDYSIGPGSKIHLV 70

Tethering Ubl4a to BAGS domain; This is the C-terminal domain of Ubiquitin-like protein 4A an ortholog of yeast Get5. In budding yeast, GET proteins directly mediate the insertion of newly synthesized TA proteins into endoplasmic reticulum membranes. Similarly, mammalian BAG6, Ubl4a, and SGTA make up a trimeric complex that binds TA proteins post-translationally and then loads them onto the cytosolic ATPase TRC40, which in turn targets them to the endoplasmic reticulum. Structural studies show that this C-terminal TUGS domain of Ubl4a is essential for BAG6 tethering. Given that BAG6 mediates oligomeric complex formation of Ubl4a, TRC35, and TRC40 (mammalian counterparts of Get5, Get4, and Get3, respectively), the C-terminal TUGS domain might be crucial for supporting BAG6-mediated Ubl4a-TRC35 complex formation in humans as an alternative to the direct Get5-Get4 interaction in yeast.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 44662819    91 WHQLGLVLAKHFEPQDAKAVLQLLRQEHEERLQKISLEHLEQLAQYL 137
Cdd:pfam17840   1 WHQLSQVLAKHFSPADAERVLEQLRRDYERSLQRLSLDDIERLAQRL 47

Ubiquitin family; This family contains a number of ubiquitin-like proteins: SUMO (smt3 homolog), Nedd8, Elongin B, Rub1, and Parkin. A number of them are thought to carry a distinctive five-residue motif termed the proteasome-interacting motif (PIM), which may have a biologically significant role in protein delivery to proteasomes and recruitment of proteasomes to transcription sites.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 44662819     3 LTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINV 69
Cdd:pfam00240   1 ITVKTLDGKKITLEVDPTDTVLELKEKIAEKEGVPPEQQRLIYSGKVLEDDQTLGEYGIEDGSTIHL 67

ubiquitin-like (Ubl) domain found in midnolin and similar proteins; Midnolin, also termed midbrain nucleolar protein, is a nucleolar protein that may be involved in regulation of genes related to neurogenesis in the nucleolus. It is strongly expressed at the mesencephalon (midbrain) of the embryo in day 12.5 (E12.5) mice and its expression is developmentally regulated. Midnolin plays a role in cellular signaling of adult tissues and regulates glucokinase enzyme activity in pancreatic beta cells. It can also control development via regulation of mRNA transport in cells. Midnolin contains an N-terminal conserved ubiquitin-like (Ubl) domain with a beta-grasp Ubl fold, a common structure involved in protein-protein interactions.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 44662819  10 GQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKhLSDYCIGPNASINVI 70
Cdd:cd01804  10 GGRFELSVPPNETVEGLKRRISKKLKVPKERITLLHKEKQLKDGT-LRENGIGDGSKLTLL 69

ubiquitin-like (Ubl) domain found in the Rad23 protein family; The Rad23 family includes the yeast nucleotide excision repair (NER) proteins, Rad23p (in Saccharomyces cerevisiae) and Rhp23p (in Schizosaccharomyces pombe), their mammalian orthologs HR23A and HR23B, and putative DNA repair proteins from plants. Rad23 proteins play dual roles in DNA repair as well as in proteosomal degradation. They have affinity for both the proteasome and ubiquitinylated proteins and participate in translocating polyubiquitinated proteins to the proteasome. Rad23 proteins carry an ubiquitin-like (Ubl) domain with a beta-grasp Ubl fold, and two ubiquitin-associated (UBA) domains, as well as a xeroderma pigmentosum group C (XPC) protein-binding domain. The Ubl domain is responsible for the binding to proteasome. The UBA domains are important for binding of ubiquitin (Ub) or multi-ubiquitinated substrates, which suggests Rad23 proteins might be involved in certain pathways of Ub metabolism. Both the Ubl domain and the XPC-binding domain are necessary for efficient NER function of Rad23 proteins.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 44662819   1 MFLTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKV-PEEQQHLLFRGQLLEDDKHLSDYCIGPNASInVIM 71
Cdd:cd01805   1 MKITFKTLQQQTFEIEVEPSDTVLELKEKIEQEQGDfPASGQKLIYSGKVLKDDKTLSEYNIKEKDFV-VVM 71

ubiquitin-like (Ubl) domain found in BCL2-associated athanogene 6 (BAG6) and similar proteins; BAG6, also termed large proline-rich protein BAG6, or BAG family molecular chaperone regulator 6, or HLA-B-associated transcript 3 (Bat3), or protein Scythe, or protein G3, is a nucleo-cytoplasmic shuttling chaperone protein that is highly conserved in eukaryotes. It functions in two distinct biological pathways, ubiquitin-mediated protein degradation of defective polypeptides and tail-anchored transmembrane protein biogenesis in mammals. BAG6 is a component of the heterotrimeric BAG6 sortase complex composed of BAG6, transmembrane recognition complex 35 (TRC35) and ubiquitin-like protein 4A (UBL4A). The BAG6 complex together with the cochaperone small, glutamine-rich, tetratricopeptide repeat-containing, protein alpha (SGTA) plays a role in the biogenesis of tail-anchored membrane proteins and subsequently shown to regulate the ubiquitination and proteasomal degradation of mislocalized proteins. Moreover, BAG6 acts as an apoptotic regulator that binds reaper, a potent apoptotic inducer. BAG6/reaper is thought to signal apoptosis, in part through regulating the folding and activity of apoptotic signaling molecules. It is also likely a key regulator of the molecular chaperone Heat Shock Protein A2 (HSPA2) stability/function in human germ cells. Furthermore, aspartyl protease-mediated cleavage of BAG6 is necessary for autophagy and fungal resistance in plants. BAG6 contains a ubiquitin-like (Ubl) domain with a beta-grasp Ubl fold, which provides a platform for discriminating substrates with shorter hydrophobicity stretches as a signal for defective proteins.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 44662819   3 LTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDY 59
Cdd:cd01809   3 VTVKTLDSQNRTFTVPEEITVKEFKEHIASSVNIPAEKQRLIFQGRVLQDDKKLKEY 59

ubiquitin-like (Ubl) domain found in ubiquitin-like protein FUBI and similar proteins; FUBI is a pro-apoptotic regulatory gene FAU encoding ubiquitin-like protein with ribosomal protein S30 as a C-terminal extension. FUBI functions as a tumor suppressor protein that may be involved in the ATP-dependent proteolytic activity of ubiquitin. The N-terminal ubiquitin-like (Ubl) domain of FUBI has the beta-grasp Ubl fold, and it may act as a substitute or an inhibitor of ubiquitin or one of ubiquitin's close relatives UCRP, FAT10, and Nedd8.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 44662819  14 SLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINV 69
Cdd:cd01793  12 TLEVSGNETVADIKAHIAALEGIAVEDQVLLYAGAPLEDDVVLGQCGIPDLATLEV 67

ubiquitin-like (Ubl) domain found in Saccharomyces cerevisiae proteasome interacting protein Dsk2p and similar proteins; The family contains several fungal multiubiquitin receptors, including Saccharomyces cerevisiae Dsk2p and Schizosaccharomyces pombe Dph1p, both of which have been characterized as shuttle proteins transporting ubiquitinated substrates destined for degradation from the E3 ligase to the 26S proteasome. They interact with the proteasome through their N-terminal ubiquitin-like domain (Ubl) and with ubiquitin (Ub) through their C-terminal Ub-associated domain (UBA). S. cerevisiae Dsk2p is a nuclear-enriched protein that may involve in the ubiquitin-proteasome proteolytic pathway through interacting with K48-linked polyubiquitin and the proteasome. Moreover, it has been implicated in spindle pole duplication through assisting in Cdc31 assembly into the new spindle pole body (SPB). S. pombe Dph1p is an ubiquitin (Ub0 receptor working in concert with the class V myosin, Myo52, to target the degradation of the S. pombe CLIP-170 homolog, Tip1. It also can protect Ub chains against disassembly by deubiquitinating enzymes.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 44662819   3 LTVKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCI 61
Cdd:cd16106   3 VTVKCSNGKKFTVEVEPDATVLELKELIAEKSDIPAEQQRLIYKGKILKDEETLSSYKI 61

ubiquitin-like (Ubl) domain found in IQ and ubiquitin-like domain-containing protein (IQUB) and similar proteins; IQUB is an IQ motif and ubiquitin domain-containing protein that may play roles in cilia formation and/or maintenance. It contains a conserved ubiquitin-like (Ubl) domain with a beta-grasp Ubl fold, a common structure involved in protein-protein interactions.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 44662819   4 TVKLLL---GQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINVIMQ 72
Cdd:cd17061   4 TVKFVLmpsGQVITLAFTLGQTIGELKEHFSSELKIPPDVLQIMFDGKLVEDNTTLVDLGVRPNGTIQLEMS 75

UV excision repair protein Rad23; All proteins in this family for which functions are known are components of a multiprotein complex used for targeting nucleotide excision repair to specific parts of the genome. In humans, Rad23 complexes with the XPC protein. This family is based on the phylogenomic analysis of JA Eisen (1999, Ph.D. Thesis, Stanford University). [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 44662819     1 MFLTVKLLLGQRCSLKVSGQESVATLKRLVSR---RLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASInVIMQPLEKM 77
Cdd:TIGR00601   1 MTLTFKTLQQQKFKIDMEPDETVKELKEKIEAeqgKDAYPVAQQKLIYSGKILSDDKTVKEYKIKEKDFV-VVMVSKPKT 79

                          90
                  ....*....|..
gi 44662819    78 ALKEAHQPQTQP 89
Cdd:TIGR00601  80 GTGKVAPPAATP 91

Beta-grasp ubiquitin-like fold; Ubiquitin is a protein modifier that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. The ubiquitination process comprises a cascade of E1, E2 and E3 enzymes that results in a covalent bond between the C-terminus of ubiquitin and the epsilon-amino group of a substrate lysine. Ubiquitin-like proteins have similar ubiquitin beta-grasp fold and attach to other proteins in a ubiquitin-like manner but with biochemically distinct roles. Ubiquitin and ubiquitin-like proteins conjugate and deconjugate via ligases and peptidases to covalently modify target polypeptides. Some other ubiquitin-like domains have adaptor roles in ubiquitin-signaling by mediating protein-protein interaction. In addition to Ubiquitin-like (Ubl) domain, Ras-associating (RA) domain, F0/F1 sub-domain of FERM (Four.1 protein, Ezrin, Radixin, Moesin) domain, TGS (ThrRS, GTPase and SpoT) domain, Ras-binding domain (RBD), Ubiquitin regulatory domain X (UBX), Dublecortin-like domain, and RING finger- and WD40-associated ubiquitin-like (RAWUL) domain have beta-grasp ubiquitin-like folds, and are included in this superfamily.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 44662819   5 VKLLLGQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINVI 70
Cdd:cd00196   3 VETPSLKKIVVAVPPSTTLRQVLEKVAKRIGLPPDVIRLLFNGQVLDDLMTAKQVGLEPGEELHFV 68

ubiquitin-like (Ubl) domain 1 found in leukocyte antigen F (HLA-F) adjacent transcript 10 (FAT10) and similar proteins; FAT10, also termed ubiquitin D (UBD), or diubiquitin, is a cytokine-inducible ubiquitin-like (Ubl) modifer that is highly expressed in the thymus, and targets substrates covalently for 26S proteasomal degradation. It is also associated with cancer development, antigen processing and antimicrobial defense, chromosomal stability and cell cycle regulation. FAT10 is presented on immune cells and under the inflammatory conditions, is synergistically induced by interferon gamma (IFNgamma) and tumor necrosis factor (TNFalpha) in the non-immune (liver parenchymal) cells. FAT10 contains two Ubl domains. The family corresponds to the first Ubl domain of FAT10. Some family members contain only one Ubl domain.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 44662819  10 GQRCSLKVSGQESVATLKRLVSRRLKVPEEQQHLLFRGQLLEDDKHLSDYCIGPNASINVIMQ 72
Cdd:cd17052   9 WDLMTFDANPQDSVKKINEHVRSKTKVPVQDQVLLLGSKILKPRRRLSSYGIDKEKTIHLTLK 71